Darths & Droids has Chancellor Valorum as such an over-the-top Evil Chancellor that he yells "Kneel before Valorum!", as a reference to Zod from the Superman film. Both Chancellor Valorum and Zod were played by Terence Stamp, whom the authors felt "deserved some slightly more memorable lines." The "GM plans" also had Valorum originally named as "Zod".
In a Concerned strip, Dr. Breen is seen reading a news paper and mentioning there is an I Spy marathon running that night. In Half-Life 2, Dr. Breen was voiced by Robert Culp, who played Kelly Robinson in I Spy.
Canadian Flash master Ian Kirby of Broken Saints fame makes a cameo on the DVD voice tracks as a Canadian soldier.
One KateModern video posted by Gavin is entitled "Half the Week Away", a reference to Oasis' "Half the World Away", the Theme Song to The Royle Family. Gavin is played by Ralf Little, who played Antony in The Royle Family.
Kajetokun is the author, actor, and editor of several famous You Tube Poops.''A day in the life of Dracula'' has the lord of evil panicing over the arrival of longtime rival. He accidentally calls Belmont "Ballmont." Kajetokun is also the author of the "Over Nine Thousand" meme.
Episode 3 of Anime Olympics has Steve being beat up by his costar at any negative comments on Magical Girl Lyrical Nanoha. Of course, said costar just happens to be Nanoha's VA Cristina Valenzuela.
Legend of Neil, a Zelda parody, has a musical episode, during which the Fairy (played by Felicia Day) states rather casually that she's "not really into online musicals", referencing the fact that one of Felicia Day's most famous roles is Penny of Dr. Horrible's Sing-Along Blog, an Emmy winning online musical. She of course makes this statement just before bursting into song.
Speaking of Felicia Day and Dr. Horrible, let's not forget Penny's line to Captain Hammer from the number A Man's Gotta Do, "I wonder what you're captain of?" Three guesses whoplays Captain Hammer. (Bonus points for it being another Joss Whedon production)
This entry borders between this and a bout of comedic prophesy: in LittleKuriboh's flagship work, an episode shows Tristan coming up on a motorcycle, and when he's asked about it, he replies: 'In the Future, card games will be played on ''motorbikes''.' Fast Forward to the Dub release of Yu-Gi-Oh! 5Ds, and we see Frank Frankson, Tristan's voice actor cast as the lead character of said show, Yusei Fudo.
In one Two Best Friends Play video, when Matt and Pat are playing Captain America: Super Soldier they come across a picture of pre-Red Skull Hugo Weaving. They take turns wondering why Elrond, Agent Smith, Megatron, and V would have portraits in a German castle before running out of Hugo Weaving movies they can remember.